any H55F and split transfer case experts?

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coldtaco

coldtaco

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Got the dreaded fluid transfer problem from the H55F to the split transfer case. Last spring we installed a Marks gears gear set in the transfer case and since then have been having this leak. Replaced the seal between the transmission and transfer case twice and still no luck. Anyone got any ideas? This is quite annoying. Thanks.
 
Did you replace the tranny output seal?
 
Clean out the transfer case vent. when it gets clogged up it allows the t-case to build pressure and force the fluid from the low point (t-case) to the trans (high point). that should fix the problem.


Dynosoar:zilla:
 
If gear oil is being siphoned out of the trans case into the tranny, you could drill and tap each fill plug, install a barbed fitting in each and hose to connect the two...automatically redirects tranny overflow back to the transfer case. Kind of a band-aid fix but works nonetheless. But by the sound of your original post, you've got fluid transfer going the other way.
 
There is a o-ring that seals between the output shaft and gear(it gets compressed inbetween the gear and bearing) that prevents fluid from finding its way between the shaft and gear,if you pull the gear off it will be just in front(facing rear of truck) of the bearing.
Just to make sure are you installing the seal the correct way? spring side of the seal faces towards the engine
 
Check out the idler shaft O ring as well. Its less common to have the transfer of fluid this way. Most guys have the fluid going up from the t-case to the transmission and then its nearly always a blocked t-case vent as Dynosoar said.

The hose trick actually solves the problem by venting the t-case to the transmission rather than moving any volume of fluid.
 
coldtaco said:
I was wondering about this o-ring. My parts/maintenance book shows this o-ring but the parts page at the dealer does not show this o-ring:confused: Anyone happen to know the part number for this? Thanks also for the hint on the big seal
Click to expand...

For some reason I remember The local Toyota dealer could not find it on the parts page either,lists it for the auto but not the manual tranny.I took it to a local seal and bearing shop and they matched it up,size is 35mm x 42mm x 3.5mm if this may help.I have a extra one if you are local...:cheers:
 
That o-ring is for the t-case in an automatic application. With a manual tranny it isn't used.

Otherwise, it almost has to be the seal between the two, or maybe the rear o-ring on the idler shaft. I'd have to go back and look at the manual to look for other possible connections.

Was this transfer case originally behind this transmission or was it a swap? If you had a 4 speed, there is a bolt hole you have to plug.

You may be stuck pulling both units and doing a more thorough rebuild of the seals.
 
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